Paleomagnetism of the Scourie Dykes of Lewisian Foreland, NW Scotland: Resolutions for the Kenorland Supercontinent Assembly During Early Paleoproterozoic

The Scourie dyke swarm in the Lewisian foreland of northwest Scotland provides key constraints on the Paleoproterozoic evolution of the North Atlantic craton. High-precision U-Pb geochronology identifies two distinct intrusive phases at ~2.41-2.38 Ga and ~2.00 Ga. However, despite decades of work, the regional paleomagnetic record is sparse and commonly compromised by Laxfordian overprints, leaving the position of the Lewisian within early Proterozoic reconstructions equivocal, which motivates our paleomagnetic study and a re-evaluation of paleogeography. We report new paleomagnetic data from seventeen dated dykes, including the first positive baked-contact tests for this region, demonstrating that primary remanent magnetizations are preserved despite later Laxfordian metamorphism. Both the ~2.4 Ga and ~2.0 Ga dyke suites record dual-polarity mean directions: Dec = 122.2°, Inc = -77.2°, α95 = 4.4°, k = 65.5, consistent with high-latitude emplacement, and Dec = 280.9°, Inc = 49.5°, α95 = 2.4°, k = 317.6, respectively, after excluding sites overprinted by younger events. The new data support alternative paleogeographic scenarios: at ~2.4 Ga, the Lewisian may have occupied a near-polar position, close to or part of the Yilgarn craton of Australia, and by ~2.0 Ga, it had moved to subtropical latitudes and most likely amalgamated with Laurentia in the north. This dual-age record highlights the transition from the breakup of the Kenorland supercontinent and emphasizes the Lewisian foreland as a keystone in early Proterozoic supercontinent reconstructions.